Cryotherapy Performed on Par With Topical Anesthetics in Young Dental Patients
A randomized clinical trial in children aged 7 to 10 years found that cryotherapy eased injection-related discomfort about as well as standard topical anesthetic agents, while offering a different behavioral advantage at the chairside. The study compared chilled distilled water, lidocaine spray, benzocaine gel, and cooled lidocaine spray before buccal infiltration anesthesia for first-time dental treatment in healthy pediatric patients.
Pain relief was not the only issue under observation. Investigators also tracked anxiety, physiological responses, taste acceptability, and treatment compliance, aiming to capture the full experience of a child facing local anesthetic injection for the first time.
Four Pre-Injection Approaches, One Shared Clinical Goal
The trial enrolled 100 children and assigned them to four groups of 25. Each child had no prior dental treatment experience, was literate, had ASA physical status I-II, and showed cooperative behavior with a Modified Dental Anxiety Scale score below 19. Children with symptomatic teeth were excluded, leaving a cohort receiving treatment for asymptomatic primary maxillary molars through restorative care, pulpotomy, or extraction.
The intervention design was straightforward. One group received 10% lidocaine spray, another 20% benzocaine gel, a third received distilled water cooled to +4 °C, and the fourth received lidocaine spray also cooled to +4 °C. All materials were applied to dried mucosa with a cotton pellet for 20 seconds before buccal infiltration anesthesia with 4% articaine and epinephrine.
That setup matters clinically because the comparison was not between cryotherapy and placebo, but between cryotherapy and agents already used in routine pediatric dentistry. The question was whether a cold stimulus alone could perform with similar analgesic and behavioral effects.
Pain Scores Did Not Separate the Groups
On the primary endpoint, pain measured with the Wong-Baker FACES Pain Rating Scale did not differ significantly across the four arms. Anxiety scores and physiological measures followed the same pattern. Modified Dental Anxiety Scale results, Facial Image Scale scores, pulse rate, oxygen saturation, and taste acceptability all failed to show significant between-group differences.
A single physiologic pattern stood out: pulse rate rose from the pre-operative to the post-operative period in every group, with no significant group-by-time interaction. The increase likely reflects the stress of the injection itself rather than any clear advantage of one pre-treatment over another in dampening autonomic arousal.
The absence of a clear pain hierarchy is clinically important. If the goal is simply to blunt the sensation of needle insertion in a child undergoing first-time dental care, cryotherapy did not underperform the conventional topical agents used in this trial.
Compliance Favored the Cold Water Arm
Behavioral cooperation told a different story. FRANKL behavior scores were significantly higher in the cryotherapy-distilled water group than in the gel and cooled-spray groups. The finding was described as exploratory, but it is still clinically relevant because cooperation can determine whether a pediatric procedure is completed smoothly or becomes a struggle for both child and clinician.
In practical terms, a child who remains more cooperative during injection can make the entire appointment more manageable. For pediatric dentistry, this matters as much as small differences in self-reported pain, especially when the child has never experienced dental treatment before and may be judging the procedure through fear rather than through prior knowledge.
Taste acceptability did not differ significantly among groups. That is useful because sensory acceptance often shapes how children respond to oral medications and topical products. A treatment that feels or tastes unpleasant can undermine cooperation even when analgesia is adequate.
Why Cryotherapy May Work Without Medication
The biological rationale for cryotherapy is plausible. Cooling the oral mucosa can reduce nerve conduction velocity, dampen nociceptor activation, and temporarily blunt the local response to needle penetration. In a setting where topical anesthetics act by blocking voltage-gated sodium channels, cold exposure may provide a parallel route to lowering perceived pain without adding pharmacologic burden.
That may be especially appealing in children, where minimizing drug exposure and simplifying the pre-injection routine can help both clinicians and families. The trial also used a cooled lidocaine spray arm, which makes the comparison more informative: the effect was not simply due to chilled fluid alone, but to the interaction between temperature and the intervention type.
Even so, the data do not support overstating the finding. Cryotherapy did not clearly beat topical anesthetics on pain or anxiety, and the behavioral advantage in compliance needs confirmation.
What the Trial Can and Cannot Support
This study was carefully designed and registered, with ethics approval, allocation concealment, blinded outcome assessment, and a defined sample size calculation. The total sample size was 100 children, exceeding the minimum calculated requirement of 76 participants. The trial also collected repeated physiological measures at three time points, which strengthens the assessment of stress response.
Still, the clinical message remains specific rather than expansive. The cohort included only cooperative children with no prior dental experience and no symptomatic teeth. All procedures involved maxillary molar injections under standardized conditions, so the findings do not automatically extend to more anxious children, more painful procedures, or different anesthetic techniques.
The study was also not powered or designed as a non-inferiority trial, so equivalence between cryotherapy and topical anesthetics cannot be claimed. What it does show is narrower: in a pediatric dental injection setting, chilled distilled water performed similarly to lidocaine spray and benzocaine gel on pain and anxiety outcomes, while showing a higher compliance score in exploratory analysis.
A Practical Question for Pediatric Dentistry
For clinicians, the appeal of cryotherapy is obvious. It is inexpensive, easy to apply, and free of the pharmacologic issues tied to topical anesthetics. If future non-inferiority trials reproduce these findings, cold application could become a practical option for reducing injection distress in children, especially in settings where simplicity and acceptability matter.
For now, the trial leaves pediatric dentists with a restrained but useful message: cryotherapy did not outperform established topical anesthetics on pain, but it also did not underperform them, and it may support better cooperation at the chairside. The next step is to test whether that behavioral edge persists in larger, more diverse pediatric samples and in children with greater baseline anxiety.